Mark Spencer
Age: 28
Company: Digium
Funding: Self-funded
Digium created and supports Asterisk, one of the hottest open-source projects on the Web. Asterisk provides more calling features than traditional phone systems, but at a fraction of the cost, Digium says. The system has been downloaded hundreds of thousands of times and attracted the attention of such giants as Intel, which signed a development deal with Digium in 2005. Unlike entrepreneurs looking for a quick buck, Digium founder and CEO Spencer has stayed focused on his product and community of open-source contributors, resisting outside capital for now. Meantime, Digium is growing like a weed. Because Asterisk is available free over the Web, users get in touch only when they want or need support, letting Spencer focus on the product and partnerships.
Advice: "Speak to as many successful people as you can," Spencer says. "You'll get lots of advice, much of it contradictory, but your job as the entrepreneur is to figure out how it all applies to you and your business."